Expert: Kenton Scott - 8/29/2008

Question
I own a Bb cornet S/N 11214, which has accessory tubing, which converts it to a C instrument. Very useful, but the conversion has tonality problems that are not consistent.
  Have you run into this before? Either way, have you any suggestions for improved tonality, besides lip muscle? (>;
  It does a good job in Bb, so I don't want to change that!

Answer
My guess is that you really have a High Pitch Bb/A cornet.  When you try to use it as a C instrument, it is flat and you can't get it up to pitch, is that correct?  

Back in the days when this horn was made, no one had settled on what the correct pitch should be.  Back in the Civil War days, about the only way you could easily get a band to play in tune was to buy all the instruments from the same maker.  

By the 1900s things were a little better but they still hadn't decided between high pitch and low pitch (A=440).  Consequently, makers would sometimes make conversion tubing for their instruments so they would play both at High pitch and Low pitch.  And, although some makers also made horns that would convert from C to Bb and to A, most just did Bb to A.  I have only seen Bb/A Bueschers.  

And, it is possible to convert a High pitch horn to low pitch.  And, sometimes that is a good solution for example with it is a straight Bb high pitch instrument.  But(if I'm correct as to the reason it plays as it does), since yours plays in tune in Bb there is really no good reason to convert it.  It is not going to go to C in any case, and you probably have little reason to play it in A.